As far as the Marlin is concerned, I'd recommend getting an owners manual from the factory. The instructions are quite clear, mine even used illustrations. You can reach Marlin at 203-239-5621. Tell them you don't have a manual and they'll hop to it. Another option is picking up one of the Firearms Disassembly manuals at the local book store. These books go even further describing take down if your so inclined.
Cleaning the other lever guns takes (1) CARE and (2) a MUZZLE GUARD. Just take your time and make sure the muzzle guard stays in place. A tip I picked up was placing a rag in the open action low enough to allow the bore brush to pass through the action. This soaks up any extra cleaning solvent and the associated gunk from cleaning. Depending on how much your shooting the Winchester and Rossi, you may want to have a gunsmith do a complete detailed cleaning every once in a while. Can't hurt.
The disassembly books I mentioned before should include the Winchester and Rossi, but complete disassembly can get hairy. Thats one of the reasons I bought the Marlin, I lean toward the lazy side when it comes to cleaning.
Hope this helps